* Intuit buys personal finance site Mint.com for $170 mln
* Intuit to use Mint.com technology on Quicken.com site
BOSTON, Sept 14 (Reuters) - Intuit Inc (INTU.O) is buying Mint.com after an unsuccessful attempt to build a rival web-based personal financial software service under its Quicken brand.
The deal is part of Chief Executive Brad Smith's drive to expand offerings of web-based services, a market that is growing far faster than the PC-based software the company has sold since it was founded in 1983.
The software maker said Monday it will pay about $170 million in cash for Mint.com, which has more than 550,000 active users of its service that helps track personal finances over the Web.
Intuit launched a rival product in January 2008, initially charging $2 per month for the Quicken Online service. The other key player in the field is Microsoft Corp (MSFT.O)
Intuit stopped charging for the product in October 2008 because of difficulty competing with Mint.com, which is free and makes money referring users to banks and other advertisers.
Intuit Senior Vice President Dan Maurer said in an interview that Quicken Online has "many fewer" active customers than Mint.com, though he declined to elaborate.
While Intuit will continue to offer a service using the Quicken Online brand, it will switch over to the Mint.com technology and advertising model. Quicken Online currently does not include any advertising.
Mountain View, California-based Intuit said it expects to close the deal in the fourth quarter of this year. It will reduce fiscal year 2010 per-share profit excluding items by about 2 cents. (Reporting by Jim Finkle; Editing by Tim Dobbyn)